A review of 250 patients with the catastrophic antiphospholipid (Asherson's) syndrome (CAPS) taken from the web site organized by the Europhospholipid Group (http://www.med.ub.es/MIMMUN/FORUM/CAPS.HTM) is presented in this paper. A short historical overview of the antiphospholipid syndrome (APS) is followed by a description of the "triggering" factors, associated autoimmune diseases, clinical presentation, presumed pathogenesis, prognosis, mode of death and suggested therapies. Triggering factors are present in approximately 50% of patients and consist predominantly of infections, trauma, including minor surgical procedures such as biopsies, obstetric-related multiorgan failure and malignancy-associated CAPS. The patients present mainly with multiorgan failure resulting from predominantly small vessel occlusions affecting mainly intra-abdominal organs such as bowel, liver, pancreas, and adrenals, although large vessel occlusions do occur and comprise mainly deep vein thromboses (DVT) of the veins of the lower limbs and arterial occlusions causing strokes and peripheral gangrene. They do not however dominate the clinical picture. The condition differs considerably from the simple/classic APS in several respects, viz. the rapid development of multiorgan failure following the above-mentioned identifiable precipitating factors, the involvement of unusual organs such as bowel, reproductive organs, and bone marrow, complicating features of disseminated intravascular coagulation in 20% of cases, the acute (adult) respiratory distress syndrome (ARDS) in one third of patients, and severe thrombocytopenia; these not being encountered in the simple/classic APS. Treatment consisting of regular and repeated plasma exchanges using fresh frozen plasma, and IV immunoglobulins in addition to parenteral steroids and anticoagulation are necessary to improve the survival in a condition where the mortality is still of the order of 50%. Treatment may have to be continued for several weeks. Parenteral antibiotics may be indicated where an underlying infection is suspected. Antifungal therapy may also be indicated with prolonged treatment and the use of the monoclonal anti-CD20 molecule, Rituximab, has proven useful in those patients where thrombocytopenia poses a major risk of hemorrhage.